Hallicrafters SX-18
第一章 SX-18Hallicrafters SX-18 SYK CHALLENGERは1938年に製造されました．
9球 5バンド 0.54～38MHz REJECTION チューニング バンドスプレッドダイヤルは360度を3回転して約1000度に展開されます． REJECTIONチューニング
取り扱い説明書では次のように説明されています． SX-18の特徴はこのREJECTION回路で，LCの直列共振回路で混信除去機能を実現しています． リジェクターは、受信機がバンド #4 および #5 で動作している場合にのみ回路に切り替えられます。 使用する必要がある特定の較正済みメモリ版の後ろにライトが現れます。 受信機を 14 MC、つまり 20メートルのアマチュアバンドで操作してみましょう。 バンドをチューニングする際に、ある商業局のイメージを横切りますが、この局の基本波は、受信機のIF 増幅器がチューニングされた周波数の 2 倍で 20 メートルバンドから除去されることは周知の事実です。校正済みリジェクターダイヤルで、14MC付近のリジェクターコントロールを慎重に調整してください。適切に調整すると、同調した周波数の受信機の感度に重大な影響を与えることなく、イメージが完全に除去されます。 イメージが気にならない周波数で受信しており、リジェクターを使用したくない場合は、リジェクター回路がカバーする 2つのアマチュアバンドのコントロールを次のように設定します。 回路図
HALLICRAFTERS SX-18 THE IMAGE REJECTORTHE REJECTOR CIRCUIT INCORPORATED IN THE SKY CHALLENGER. REPRESENTS A NOTEWORTHY CONTRIBUTION BY THE HALLICRAFTERS TO IMAG E-FREE HIGH FREQUENCY RECEPTION. IT HAB LONG BEEN APPRECIATED THAT ADDITIONAL STAGES OF RADIO FREQUENCY AMPLIFICATION WAS NOT THE CORRECT ANSWER TO IMAGE BUPPRESSION. THROUGH THE UBE OF THE "INFINITE IMAGE REJECTOR" IN THE SKY CHALLENGER I ALL PREVIOUS IMAGE RATIOS ARE OUT-MODED. REJECTION OF INFINITY IT IS NOW POSSIBLE. THE REJECTOR IS UNIQUE. BECAUSE OF THAT YOUR ATTENTION IS CLOSELY DRAWN TO THE PROPER OPERATION OF THE CONTROL AS WELL AS WHAT TO EXPECT FROM ITS USE. THE REJECTOR IS SWITCHED INTO THE CIRCUIT ONLY WHEN THE RECEIVER IS OPERATED ON BANDS #4 AND #5. YOU WILL NOTICE A LIGHT APPEAR BEHIND THE PARTICULAR CALIBRATED BOALE THAT SHOULD BE USED. LET US OPERATE THE RECEIVER ON THE 14 MC, OR 20 METER AMATEUR BAND. IN TUNING ACROSS THE BAND YOU RUN ACROSS THE IMAGE OF SOME COMMERCIAL STATION, THE FUNDAMENTAL OF THIS STATION AS WE ALL KNOW IS REMOVED FROM THE 20 METER BAND BY DOUBLE THE FREQUENCY TO WHICH THE IF AMPLIFIER OF THE RECEIVER IS TUNED. NOW ADJUST THE REJECTOR CONTROL CAREFULLY IN THE VICINITY OF 14 MC ON THE CALIBRATED REJECTAR DIAL. WHEN PROPERLY ADJUSTED THE IMAGE WILL BE COMPLETELY ELIMINATED WITHOUT SERIOUSLY AFFECTING THE SENSITIVITY OF THE RECEIVER ON THE FREQUENCY TO WHICH IT HAD BEEN TUNED. SHOULD YOU BE LISTENING AT A FREQUENCY NOT BEING BOTHERED WITH IMAGES, AND YOU DO NOT WISH TO USE THE REJECTOR LEAVE THE CONTROL AS FOLLOWS FOR THE TWO AMATEUR BANDS COVERED BY THE REJECTOR CIRCUIT. 20 METERS-14 MC NOTE: LEAVE THE REJECTOR AT APPROXIMATELY 15 MC. (ON THIS BAND THE HIGH FREQUENCY OSCILLATOR IS ON THE HIGH-FREQUENCY SIDE). THE 7MC ON 40 METER BAND IS ALSO ON BAND #4 OF THE RECEIVER. WHEN RECEIVING ON 40METERS THE REJECTOR CONTROL SHOULD BE LEFT 9 MC. USE OF THE REJECTOR CIRCUIT ON THIS BAND IS NOT NECESSARY. 10 METERS 28Mc: LEAVE THE REJECTOR AT APPROXIMATELY 27Mc . (THE OSCILLATOR IS ON THE LOW FREQUENCY BIDE ON THIS BAND). CAUTION: SHOULD YOU NOT BE ABLE TO GET SIGNALS THROUGH AT ALL CHECK THEBETTING OF THE REJECTOR CONTROL. IT IS POSSIBLE THAT YOU HAVE THE REJECTOR CONTROL AT A POINT WHERE THE FREQUENCY TO WHICH YOU WISH TO LISTEN IS BEING REJECTED, OR "BEING DROPPED IN THE SLOT". ALWAYS REMEMBER TO KEEP THE REJECTOR CONTROL SET AT APPROXIMATELY THE SAME FREQUENCY AS THAT TO WHICH YOU ARE LISTENING. WHEN YOU MEVE THE MAIN TUNING CONTROL FOLLOW UP WITH THE REJECTOR OR OTHERWISE YOU WILL RUN INTO THE POSSIBILITY OF LEAVING YOUR MAIN TUNING DIAL AT A GROUP OF FREQUENCES BEING REJECTED.
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